C/C++ 函数指针

声明函数指针，必须指定指针指向的函数类型，例如:double pam(int)；正确的指针类型为 double (*pf)(int)。与pam()声明类似，将pam替换为（*pf），这里可以pf=pam等式成立。

#include<iostream>double betsy(int);double pam(int);void estimate(int lines, double(*pf)(int));using namespace std;int main(){    int code;    cout << "How many lines of code do you need?"<< endl;    cin >> code;    cout << "Here`s Betsy`s estimate:\n";    estimate(code, betsy);    cout << "Here`s Pam`s estimate:\n";    estimate(code, pam);    return 0;}double betsy(int lns){    return 0.5*lns;}double pam(int lns){    return 0.03*lns + 0.0004*lns*lns;}void estimate(int lines, double(*pf)(int)){    cout << lines << "lines will take";    cout << (*pf)(lines) << "hours(s)\n";}

这里传入pam和besty函数到estimate中的（*pf）参数